Have product transmitting on 900 Mhz band with the CC115L. However, some devices are at a -40Khz shift while others are right on. After replace the CC115L with another one, the shift is gone. Note: There is no communication as the -40Khz seems to put it out of band.
The spec states a 40PPM. Calculating here: 40KHz/900Mhz= 44 PPM which shows out of spec.
Looks like if I reduce the over all capacitance of the bypass caps (30pf each) a bit, it should bring it back into band. But, can't good too much as it would too high on devices that don't have the lower shift.
Question is why some device seem to add to the shift while others do not? Can I assume that the circuit is on the edge of the spec and the tolerance of the device then comes into play? Keep in mind, the shift is either 40Khz or not and nothing in between.